Split "Activating optional features" article into separate GitHub Apps and OAuth Apps articles (#36684)

Co-authored-by: Sarah Edwards <skedwards88@github.com>

content/apps/maintaining-github-apps/activating-optional-features-for-github-apps.md

@@ -0,0 +1,33 @@
+---
+title: Activating optional features for GitHub Apps
+intro: 'You can test new optional features for your {% data variables.product.prodname_github_apps %}.'
+redirect_from:
+  - /developers/apps/activating-beta-features-for-apps
+  - /developers/apps/activating-optional-features-for-apps
+  - /developers/apps/getting-started-with-apps/activating-optional-features-for-apps
+  - /apps/maintaining-github-apps/activating-optional-features-for-apps
+versions:
+  fpt: '*'
+  ghae: '*'
+  ghes: '*'
+  ghec: '*'
+topics:
+  - GitHub Apps
+shortTitle: Activate optional features
+---
+{% warning %}
+
+**Warning:**  Optional features are subject to change.
+
+{% endwarning %}
+
+## Activating optional features for {% data variables.product.prodname_github_apps %}
+
+{% data reusables.apps.settings-step %}
+{% data reusables.user-settings.developer_settings %}
+3. Click **Edit** next to the {% data variables.product.prodname_github_app %} you want to enable an optional feature for.
+{% data reusables.apps.optional_feature_activation %}
+
+## Further reading
+
+- "[AUTOTITLE](/apps/maintaining-github-apps/modifying-a-github-app)"